scholarly journals Monitoring of acetochlor residues in soil and maize grain supported by the laboratory study

2014 ◽  
Vol 60 (No. 11) ◽  
pp. 496-500 ◽  
Author(s):  
M. Kucharski ◽  
M. Dziągwa ◽  
J. Sadowski
Keyword(s):  
Degradation Rate ◽  
Electron Capture Detection ◽  
Soil Medium ◽  
Degradation Data ◽  
Loamy Sand Soil ◽  
Maximum Residue Level ◽  
Time Period ◽  
Silty Loam ◽  
Loam Soil ◽  
Maize Grain

The purpose of this work was to evaluate the acetochlor degradation rate in soils and investigate acetochlor contamination of maize grains and soil. Two kinds of soil: medium silty loam (soil A) and heavy loamy sand (soil B) were collected for the laboratory experiment. The degradation data were plotted. Good linearity was found between logarithmic concentration of acetochlor residues and time, indicating first-order rates of degradation. The t<sub>1/2</sub> values varied from 10.5 days for soil A to 15.1 days for soil B. The degradation rate depends on the soil properties. In the soil A (higher content of clay and organic carbon) the t<sub>1/2</sub> value was shorter than in the soil B. Monitoring tests were carried out during the 2010&ndash;2012 time period on maize fields located in the south-western Poland. Soil and maize grain samples were collected at harvest time. The determination of acetochlor residues was conducted using gas chromatography with electron capture detection. Based on the analysis of a total of 124 environmental samples, acetochlor residues were detected in 17.4% of soil and 8.1% of maize grain samples. None of the examined samples showed a herbicide concentration exceeding the maximum residue level.

Hydrodynamic Dispersion Coefficient of Urea in Silty Loam Soil

2019 ◽  
Vol 6 (04) ◽  
Author(s):  
RAM PAL ◽  
H C SHARMA ◽  
M IMTIYAZ
Keyword(s):  
Transport Phenomenon ◽  
Porous Medium ◽  
Contaminant Transport ◽  
Dispersion Coefficient ◽  
Hydrodynamic Dispersion ◽  
Soil Columns ◽  
Soil Medium ◽  
Adverse Health Effects ◽  
Silty Loam ◽  
Loam Soil

The modern theme of agriculture is not only to increase production but also to minimize undesirable environmental effects. Leaching of surface-applied fertilizer is the major source of groundwater pollution. Nitrogenous fertilizers are the most popular among the Indian farmers, which on leaching reach the groundwater in different forms (NH4-N, NO3-N, etc). NO3-N leaches faster than other types, remains in-reactive in groundwater, moves with the velocity of groundwater and contaminates it. Contamination arises when NO3-N accumulates in groundwater and consumed in high amount by humans and animals, may result in adverse health effects. For the study of contaminant transport phenomenon in porous medium, a general convection dispersion equation is used, in which dispersion coefficient is one of the primary parameters necessary to be determined for a particular soil. Keeping it in view a study was conducted to assess different available techniques to determine the dispersion coefficient with the help of soil columns having silty loam soil as soil medium. The value of the dispersion coefficient obtained for silty loam soil, by this method was equal to 0.00576 m2.

scholarly journals Metazachlor residues in soil and rape seed

2014 ◽  
Vol 54 (1) ◽  
pp. 74-77 ◽  
Author(s):  
Mariusz Kucharski ◽  
Jerzy Sadowski
Keyword(s):  
Oilseed Rape ◽  
Soil Samples ◽  
Electron Capture Detection ◽  
Harvest Time ◽  
Winter Oilseed Rape ◽  
Rape Seed ◽  
Winter Rape ◽  
Maximum Residue Level ◽  
Time Period

Abstract The purpose of the work was to analyse metazachlor contamination of the soil and metazachlor contamination of rape seeds. Monitoring tests were carried out during the 2010-2012 time period, on winter and spring oilseed rape fields located in south-western Poland. Soil and seed samples were collected at harvest time. The determination of metazachlor residues was conducted using gas chromatography with electron capture detection (GC/ECD). Based on the analysis of a total of 59 soil samples and 59 rape seed samples, metazachlor residue was detected in 45% of the soil samples of winter oilseed rape and in 71% of the soil samples of spring oilseed rape. Metazachlor contamination of rape seed was detected in 29% of winter rape samples and in 53% of spring rape samples. The concentration of assayed residue did not exceed 0.0005-0.0102 mg/kg. There were significantly higher amounts of metazachlor residue determined for the soil and seed samples of spring oilseed rape. None of the analyzed samples of oilseed rape seed showed a residue content exceeding the Maximum Residue Level (MRL).

scholarly journals Aggregate stability and associated C and N in a silty loam soil as affected by organic material inputs

2015 ◽  
Vol 14 (4) ◽  
pp. 774-787 ◽  
Author(s):  
Pan LONG ◽  
Peng SUI ◽  
Wang-sheng GAO ◽  
Bin-bin WANG ◽  
Jian-xiong HUANG ◽  
...  
Keyword(s):  
Organic Material ◽  
Aggregate Stability ◽  
Silty Loam ◽  
Loam Soil ◽  
C And N

scholarly journals A short-term comparison of organic v. conventional agriculture in a silty loam soil using two organic amendments

2008 ◽  
Vol 146 (6) ◽  
pp. 677-687 ◽  
Author(s):  
J. F. HERENCIA ◽  
J. C. RUIZ ◽  
S. MELERO ◽  
P. A. GARCIA GALAVÍS ◽  
C. MAQUEDA
Keyword(s):  
Organic Farming ◽  
Crop Yields ◽  
Organic Amendments ◽  
Chemical Properties ◽  
Soil Nutrient ◽  
Short Term ◽  
Organic System ◽  
Conventional Agriculture ◽  
Silty Loam ◽  
Loam Soil

SUMMARYThe transition from conventional to organic farming is accompanied by changes in soil chemical properties and processes that could affect soil fertility. The organic system is very complex and the present work carries out a short-term comparison of the effects of organic and conventional agriculture on the chemical properties of a silty loam soil (Xerofluvent) located in the Guadalquivir River Valley, Seville, Spain, through a succession of five crop cycles over a 3-year period. Crop rotation and varieties were compared in a conventional system using inorganic fertilizer and two organic systems using either plant compost or manure. At the end of the study, organic farming management resulted in higher soil organic carbon (OC), N and available P, K, Fe and Zn. The available Mn and especially Cu values did not show significant differences. In general, treatment with manure resulted in more rapid increases in soil nutrient values than did plant compost, which had an effect on several crop cycles later. The present study demonstrated that the use of organic composts results in an increase in OC and the storage of nutrients, which can provide long-term fertility benefits. Nevertheless, at least 2–3 years of organic management are necessary, depending on compost characteristics, to observe significant differences. Average crop yields were 23% lower in organic crops. Nevertheless, only two crops showed statistically significant differences.

The Degradation and Bioactivity of Metolachlor in the Soil

Weed Science ◽  
1986 ◽  
Vol 34 (3) ◽  
pp. 479-484 ◽  
Author(s):  
Michael P. Braverman ◽  
Terry L. Lavy ◽  
Clyde J. Barnes
Keyword(s):  
Oryza Sativa ◽  
Organic Carbon ◽  
Incubation Time ◽  
Soil Profile ◽  
Degradation Rate ◽  
Organic Carbon Content ◽  
Silt Loam ◽  
Treated Soil ◽  
Flooded Rice ◽  
Loam Soil

In bioassays, rice (Oryza sativaL.) recovery from metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] injury tended to be slower in flooded rice, but was not significantly different from the recovery rate in a nonflooded rice. In soils treated with 1 ppm (w/w) metolachlor and incubated in constant-temperature chambers, the half-life of metolachlor was shorter at 40 C than at 30 C. The degradation rate of metolachlor was not significantly correlated with declining moisture potentials in the range of −30 to −80 kPa. The CO2evolution from metolachlor-treated soil was negatively correlated with incubation time and positively correlated to declining moisture levels. In a field study, metolachlor, as determined by bioassay, was mobile in a Taloka silt loam soil profile. After being incorporated to 7.5 cm, it became evenly distributed in the top 15 cm of the soil profile within 18 days. Metolachlor adsorption was positively correlated with clay and organic carbon content.

scholarly journals Cadmium distribution coefficeints and Cd transport in structured soils

2011 ◽  
Vol 48 (No. 3) ◽  
pp. 96-100 ◽  
Author(s):  
Ľ. Lichner ◽  
A. Čipáková
Keyword(s):  
Distribution Coefficient ◽  
Distribution Coefficients ◽  
Equilibrium Distribution Coefficient ◽  
Loamy Sand Soil ◽  
Structured Soils ◽  
Cadmium Transport ◽  
Batch Technique ◽  
The Matrix ◽  
Loam Soil ◽  
Cd Transport

In the case of cadmium transport via soil macropores, the short-term duration of an interaction between the reactive solute in aqueous phase and soil, as well as cadmium precipitation or adsorption on particles &lt; 10&ndash;5 m should be taken into account. Two distribution coefficients are proposed for predicting the cadmium transport in a&nbsp;structured soil: the matrix distribution coefficient Kdm, equal to the equilibrium distribution coefficient Kdeq&nbsp;and estimated using the conventional batch technique, and the macropore distribution coefficient KdM, estimated using the modified batch technique. It was found that the conventional approach (using the coefficient Kdeq&nbsp;only) would underestimate a&nbsp;penetration of the part of Cd transported in the macropores about 255-times in the loamy-sand soil in Kalinkovo, 20-times in the loam soil in Macov, and 122-times in the clay soil in Jurov&aacute; in comparison with the approach proposed in this study.

Assessment of implement efficiency and soil structure under different conventional tillage implements and soil moisture contents in a silty loam soil

CATENA ◽  
2017 ◽  
Vol 158 ◽  
pp. 413-420 ◽  
Author(s):  
A.A. Tagar ◽  
M.A. Gujjar ◽  
Jan Adamowski ◽  
N. Leghari ◽  
A. Soomro
Keyword(s):  
Soil Moisture ◽  
Soil Structure ◽  
Conventional Tillage ◽  
Moisture Contents ◽  
Silty Loam ◽  
Loam Soil

RATE OF THYROXINE SECRETION BY MALE AND LAYING JAPANESE QUAIL: IDENTIFICATION OF THE RADIOACTIVE THYROXINE DEGRADATION COMPONENT OF THE MULTIPHASIC 131I CURVE

1975 ◽  
Vol 65 (1) ◽  
pp. 65-71 ◽  
Author(s):  
G. A. ROBINSON ◽  
K. H. TAM
Keyword(s):  
Japanese Quail ◽  
Degradation Rate ◽  
The Body ◽  
Secretion Rate ◽  
Distribution Space ◽  
Rapid Loss ◽  
Serum Samples ◽  
Time Period

SUMMARY Counting of radioactivity in Japanese quail in vivo showed a rapid loss of 131I from the body 12–24 h after the i.v. injection of [131I]thyroxine (T4), followed by a period of slow decrease in counting rates to 96 h. From comparison of these [131I]T4 curves with curves for 131iodide-injected birds and from counts on serum and other tissues in vitro it was concluded that, for Japanese quail, the T4 secretion rate should be calculated using serum samples taken during the first 12 h. Using this time period, the parameters measured were: T4 distribution space, laying hens 45·7 and mature cocks 26·3 ml/100 g body weight; fractional degradation rate for T4, hens 5·73 and cocks 3·12/day; serum T4 concentration (Tetrasorb125 method), hens 1·20 ± 0.07 and cocks 1·34 ± 0.05 (s.e.m.)μg/100 ml (n= 16); T4 secretion rate, hens 3·14 and cocks 1·10 μg/100 g/day.

Time series outlier and intervention analysis: Irrigation management influences on soil water content in silty loam soil

2012 ◽  
Vol 111 ◽  
pp. 105-114 ◽  
Author(s):  
Basem Aljoumani ◽  
Jose A. Sànchez-Espigares ◽  
Nuria Cañameras ◽  
Ramon Josa ◽  
Joaquim Monserrat
Keyword(s):  
Time Series ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Intervention Analysis ◽  
Silty Loam ◽  
Loam Soil

Critical Levels of Selenium in Different Crops Grown in an Alkaline Silty Loam Soil Treated with Selenite-Se

2005 ◽  
Vol 277 (1-2) ◽  
pp. 367-374 ◽  
Author(s):  
N. Rani ◽  
K. S. Dhillon ◽  
S. K. Dhillon
Keyword(s):  
Critical Levels ◽  
Silty Loam ◽  
Loam Soil
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